I would suggest you don't look at it in terms of "which is better", but you will need to look at the various differences between the units and which one will work for you. Each has it's own sonic signature and good/bad points that I believe you will need to evaluate and listen to for yourself.
You never mentioned which cartridge you're going to use with it, and I think this is very important. The cartridge will have a lot of bearing on which phono stage you should be looking for. Remember the Sonic Frontiers unit can be configured (resistors) to use 3 different gain settings 44db,54db, or 62db. The BAT VK-P5 only has 50db and 55db of gain. If you're going to use a very low output cartidge (<0.6mV) then the Sonic Frontiers unit might be better, otherwise you will also probably need a step-up with the BAT unit. Don't forget it also goes the same way with too high of an output from the cartridge that you might have too high of a gain from the phono stage (I recently had this problem which caused the digital volume control on my Sim Audio preamp to clip.)
Also, are you planning on using XLR or RCA output? The BAT has ONLY XLR outputs, and the Sonic Frontier unit ONLY has RCA outputs.
I would suggest that you should also look at the Audio Research PH3SE phono stage. It is another excellent tube phono stage as well.
BTW, I ended up buying the Sonic Frontiers Phono 1, and I really like it. I bought it because I can configure it with really high gain so I can use a very low-output cartridge which I wasn't able to do with my old phono stage.
Good luck.
You never mentioned which cartridge you're going to use with it, and I think this is very important. The cartridge will have a lot of bearing on which phono stage you should be looking for. Remember the Sonic Frontiers unit can be configured (resistors) to use 3 different gain settings 44db,54db, or 62db. The BAT VK-P5 only has 50db and 55db of gain. If you're going to use a very low output cartidge (<0.6mV) then the Sonic Frontiers unit might be better, otherwise you will also probably need a step-up with the BAT unit. Don't forget it also goes the same way with too high of an output from the cartridge that you might have too high of a gain from the phono stage (I recently had this problem which caused the digital volume control on my Sim Audio preamp to clip.)
Also, are you planning on using XLR or RCA output? The BAT has ONLY XLR outputs, and the Sonic Frontier unit ONLY has RCA outputs.
I would suggest that you should also look at the Audio Research PH3SE phono stage. It is another excellent tube phono stage as well.
BTW, I ended up buying the Sonic Frontiers Phono 1, and I really like it. I bought it because I can configure it with really high gain so I can use a very low-output cartridge which I wasn't able to do with my old phono stage.
Good luck.